How to read organic chemistry structures

How to read organic chemistry structures. Khan Academy offers free, world-class education for anyone, anywhere. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright Feb 23, 2023 · An open textbook that is suitable for the first semester of Organic Chemistry. Understanding Organic Chemistry: The Aim of this instructable is to give a light overview of Organic chemistry including; Formulae, structure and identification to aid anyone who is interested in or is taking this subject. Just go as far as the compounds you are interested in at the moment and ignore the rest. Besides the fundamental discussions of organic acids-bases, stereochemistry, IR and NMR, this book also includes the topics of substitution and elimination reactions, radical substitution of alkanes, preparation Aug 16, 2022 · Organic chemistry has often been defined as the chemistry of life or the chemistry of carbon-containing compounds. k. ** Structural Formulas are written by: Nov 27, 2023 · Likewise, we can have tripeptides, tetrapeptides, and other polypeptides. Many organic molecules are too complicated to be specified by a molecular formula. By applying the formal charge guideline, the “-“ formal charge is more preferable on oxygen, which is more electronegative than nitrogen, so the 2 nd structure is the more stable one with lower energy, and makes more contribution to the actual structure in this species. In this tutorial brought to you by the ChemTalk team, you will learn about chair conformations. To determine the shapes of molecules, we must become acquainted with the Lewis electron dot structure. Adapted by Kimberly Berkowski. The relative instability of these smaller ring structures can be explained by a concept called angle strain , in which the four bonds around the sp 3 -hybridized This organic chemistry video tutorial shows you how to draw lewis structures, bond line structures and skeletal structures including condensed structural for Watch this video to learn how to draw bond-line structures for organic molecules and practice with examples. Organic Compounds. May 22, 2019 · How Serge Aced Organic Chemistry; Success Stories: How Zach Aced Organic Chemistry 1; Success Stories: How Kari Went From C– to B+; How Esther Bounced Back From a "C" To Get A's In Organic Chemistry 1 And 2; How Tyrell Got The Highest Grade In Her Organic Chemistry Course; This Is Why Students Use Flashcards; Success Stories: How Stu Aced Below is a summary, showing the relationship between Lewis/Kekule structures, line structures and condensed formulae for a few different compounds. Kekulé) structure which is helpful when you want to look at every single atom; however, showing all of the hydrogen atoms makes it difficult to compare the overall structure with other similar molecules and makes it difficult to focus Courtesy of Jeffrey S. org and *. Dec 15, 2021 · Organic Chemistry Organic Chemistry I (Liu) 6: Structural Identification of Organic Compounds- IR and NMR Spectroscopy 6. Jul 12, 2023 · In our study of organic chemistry, it will become extremely important to be able to quickly recognize the most common functional groups, because they are the key structural elements that define how organic molecules react. Basically, there are 3 common ways organic compounds are drawn. As we progress in our study of organic chemistry, it will become extremely important to be able to quickly recognize the most common functional groups, because they are the key structural elements that define how organic molecules react. Lewis structures are essential for this as they show all the bonds and electrons in the molecule. In fact, if you're starting to feel like the class is one big art lesson, read here: Organic Chemistry or Art Class? Here's my approach: Draw 2 parallel lines When switching from general to organic chemistry, showing molecules as structures rather than simple formulas becomes one of the first things and priorities you need to learn. 8 sp 2 Hybrid Orbitals Jul 23, 2024 · John McMurry's Organic Chemistry is renowned as the most clearly written book available for organic chemistry. 3. org are unblocked. (I. In condensed structures , carbon–carbon and carbon–hydrogen bonds aren’t shown. Many students try to draw the entire thing at once, but the poor hexagon tends to look drunk and wobbly. Draw a line-angle structure for the compound CH 3 CH 2 CH(CH 3)CH 2 CH 2 CH 3. The major classes of organic molecules are shown in this category and also linked on the bottom page for the number of collections of spectral information regarding organic molecules. They make up the “words” of every organic chemistry sentence, so it is vital to understand how to read and write structures. Organic molecules are usually drawn using either condensed structures or skeletal structures. Even simpler than condensed structures are skeletal structures such as those shown in Table 1. Cycloalkanes are also saturated, meaning that all of the carbons atoms that make up the ring are single bonded to other atoms (no double or triple bonds). Technically, Epoxides are ethers, but since they participate in a number of reactions that ethers generally don’t , they deserve their own category. For now, we will only worry about drawing and recognizing each functional group, as depicted by Lewis and This video provides a basic introduction for college students who are about to take the 1st semester of organic chemistry. 6c) and table (Table 6. The process involves: Identifying the number of carbons: This count determines the molecule’s core structure. In some sources, you will see condensed structures for smaller molecules instead of full Lewis structures: Figure 1. Basic concepts of the structures and reactivities of organic molecules are covered in this open textbook. If you're seeing this message, it means we're having trouble loading external resources on our website. Identifying other atoms: Bromine, oxygen, nitrogen, etc. Line structures also help in quickly getting a sense of a IUPAC Nomenclature of Organic Compounds. The 'default' in organic chemistry (essentially, the lack of any functional groups) is given the term alkane , characterized by single bonds between carbon and carbon, or between carbon 2. 10 May 9, 2022 · Video advice: How to draw SKELETAL STRUCTURES or BOND LINE STRUCTURES – Organic Chemistry Basics. This ion is called the molecular ion - or sometimes the parent ion and is often given the symbol M Being able to “read” these structures will pave the road to success in conquering whatever is next – identifying functional groups, drawing isomers, naming compounds, etc. You wouldn’t write it CH 3 CH 3 CH 3 CH 3 C ; writing it like that implies a chain, and each of those CH 3 groups can only be attached to one thing. Aug 11, 2020 · Line notations represent structures as a linear string of characters. These rules make up the system of nomenclature for naming organic molecules. RULE 1 Carbon atoms aren’t usually shown. Core Concepts. Skeletal structural formula of Vitamin B 12. For example, the molecular formula C 4 H 10 tells us there are 4 carbon atoms and 10 hydrogen atoms in a molecule, but it doesn’t distinguish between butane and 2-methylpropane. It will be more helpful if you become comfortable going from one style of drawing to another, and look at drawings and The three different ways to draw organic molecules include Kekulé Formulas, Condensed Formulas, and Skeletal structures (also called line-bond structures or line formulas). Don't try to read all these pages in one go. You'll learn how to draw resonance early in orgo 1, and be tested on resonance intermediates in advanced orgo 2 mechanisms. Learning Objectives for this chapter: Draw, recognize and read different structure formulas that represent organic molecules correctly and skillfully. To help you take away the guesswork I've put together a brand new series taking you through the basics, starting with the question: What IS Resonance, all the In organic chemistry, a popular choice is line structures (sometimes called skeletal structures). Skeletal structures are an effecient way to draw these molecules by using lines to represent C-C bonds at each vertex or line-end. In John McMurry's words, "I wrote this book because I love writing. Oct 6, 2010 · 6. 2. Learn how to name organic compounds with iso-, sec-, and tert- prefixes using common and systematic methods. The rules for drawing skeletal structures are straightforward. Hydrocarbons propose one or more acceptable Kekulé structures (structural formulas) for any given molecular formula; write the molecular formula of a compound, given its Kekulé structure. May 20, 2021 · We use several kinds of formulas to describe organic compounds. Observe the following drawings of the structure of Retinol, the most common form of vitamin A. com, featuring a new sketcher and a new viewer. This system will also be used to help describe how electrons from in reactions. Aug 29, 2013 · just a simple question from me today I was looking at the structure of Norepinephrine for a school project and was curious about the diagrams on the Wikipedia page for it. Drawing every bond and every atom is tedious, however, so chemists have devised several shorthand ways for writing structures. Organic chemistry is all about structure. Let's learn IUPAC Naming of Organic Compounds such as alkanes, alkenes, alkynes, and functional groups such as halid. Use this interactive site to master essential concepts in organic chemistry. The first drawing follows the straight-line (a. This information might be about you, your preferences or your device and is mostly used to make the site work as you expect it to. Russian Chemist Alexander Butlerov acknowledged that molecules are not random clusters of atoms and functional groups but are arranged in a concrete pattern. draw the shorthand structure of a compound, given its Kekulé structure. Update (August 2024): We created a brand new app at molview. Jun 20, 2011 · In organic chemistry, we use brackets in exactly the same way. 3. , if a carbon molecule is attached to two other carbons, then it has 2 bonded 1. But just because it comes first, doesn’t mean that you can simply tackle it and move on. Organic Chemistry is a subsect of chemistry which involves o… Organic chemistry has developed a system to show how electrons move between resonance structures. 5: Degree of Unsaturation/Index of Hydrogen Deficiency; 2. If the participants in the “shared space” all agree that they know an anionic centre has an “invisible” lone pair, then of course it is OK to start the arrow at the charge and dispense with drawing the lone pair. Although the Lewis theory does not determine the shapes of molecules, it is the first step in predicting shapes of molecules. I get great pleasure and satisfaction from taking a complicated subject, turning it around until I see it clearly from a new angle, and then explaining it in simple words. 1: Structures of Alkanes; 2. interpret shorthand structures and convert them to Kekulé structures. Jan 23, 2023 · Just as each distinct compound has a unique molecular structure which can be designated by a structural formula, each compound must be given a characteristic and unique name. Drawing Skeletal Structures! In this video, you’ll learn all about drawing organic molecules using the skeletal structure, also known as the bond-line structure. Nov 23, 2016 · How To Interpret IR Spectra In 1 Minute Or Less: The 2 Most Important Things To Look For [Tongue and Sword] Last post, we briefly introduced the concept of bond vibrations, and we saw that we can think of covalent bonds as a bit like balls and springs: the springs vibrate, and each one “sings” at a characteristic frequency, which depends on the strength of the bond and on the masses of the It is necessary to draw structural formulas for organic compounds because in most cases a molecular formula does not uniquely represent a single compound. The main way of representing organic molecules are the Bond-Line (Zig-zag) structures. One of the most common application of infrared spectroscopy is to the identification of organic compounds. Notice also in the second of the condensed structures that the two CH3 units attached to the CH carbon are grouped together as (CH3)2. 4: IUPAC Naming of Organic Compounds with Functional Groups; 2. This is a fundamental skill for understanding organic chemistry. Used with permission. Jul 20, 2022 · Much of the remainder of your study of organic chemistry will be taken up with learning about how the different functional groups behave in organic reactions. Sep 23, 2022 · There are a series of rules for naming branched alkanes (and, ultimately, for all organic compounds). Watch the video and master orgo1reviewpreviewplaylist. kasandbox. for more information) Note that the names of alkenes have the same stem as the alkane with the same number of carbon atoms in its chain but have the ending –ene. One of the fundamental differences of Organic Chemistry from General Chemistry is the need for having a much better visualization and understanding of the molecular structures. Aug 13, 2024 · Notice also in the second of the condensed structures that the two CH 3 units attached to the CH carbon are grouped together as (CH 3) 2. In organic chemistry we make use of different types of formulas for this reason. Draw the Line-Angle structure for the molecule below. 9: Structure Determination Practice; 6. Jan 16, 2018 · How Serge Aced Organic Chemistry; Success Stories: How Zach Aced Organic Chemistry 1; Success Stories: How Kari Went From C– to B+; How Esther Bounced Back From a "C" To Get A's In Organic Chemistry 1 And 2; How Tyrell Got The Highest Grade In Her Organic Chemistry Course; This Is Why Students Use Flashcards; Success Stories: How Stu Aced May 27, 2024 · When the vaporized organic sample passes into the ionization chamber of a mass spectrometer, it is bombarded by a stream of electrons. Introduction. Valence electrons are those of an atom’s outermost shell. 7 sp 3 Hybrid Orbitals and the Structure of Ethane; 1. The other one isn't so obvious until you look at the structure in detail. Dec 15, 2021 · 2. The structural formula of a chemical compound is a graphic representation of the molecular structure (determined by structural chemistry methods), showing how the atoms are possibly arranged in the real three-dimensional space. Register – it’s free! register. In your answer, you touch upon something we often take for granted, but which I will call “implicit semantics”. Figure: Different Representations of a Polypeptide (Heptapeptide) In order to name organic compounds you must first memorize a few basic names. 6 sp 3 Hybrid Orbitals and the Structure of Methane; 1. 5. Let us know what you think! Dec 16, 2021 · Most protons in organic compounds have chemical shift values between 0 and 12 ppm relative to TMS, although values below 0 ppm and above 12 ppm are occasionally observed. Chemical shift is associated with the Larmor frequency of a nuclear spin to its chemical environment. For example, the molecular formula C 4 H 10 tells us there are 4 carbon atoms and 10 hydrogen atoms in a molecule, but it does not distinguish between butane and isobutane. The skeletal formula, line-angle formula, bond-line formula or shorthand formula of an organic compound is a type of molecular structural formula that serves as a shorthand representation of a molecule's bonding and some details of Hybridization is a concept that explains the formation of chemical bonds and the shapes of molecules. Draw the Lewis structure of the molecule below, showing all atoms and all valence electrons (bonds and lone pairs). But this is actually a misnomer. No common thread here; just a few more prominent functional groups worth knowing. The chemical shift value of hydrogens in certain structural environment, or common organic functional groups, are listed in chart (Fig. Tetramethylsilane (TMS, \(\ce{(CH3)4Si}\)) is generally used as an internal standard to determine chemical shift of compounds: δ TMS =0 ppm. e. Aug 10, 2018 · About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright In this chapter, we will discuss the fundamental structural features of organic compounds, the categorization and drawing of organic structures, functional groups, and nomenclatures. See examples, practice problems, and tips for drawing and understanding molecules. 6: Intermolecular Force and Physical Properties of Organic Compounds; 2. " In Organic Chemistry: A The skeletal formula of the antidepressant drug escitalopram, featuring skeletal representations of heteroatoms, a triple bond, phenyl groups and stereochemistry. A compound can have multiple Lewis Structures that contribute to the shape of the overall compound, so one Lewis structure of a compound may not necessarily be exactly what the compound looks like. OrgChem101 Modules. . When you visit any website, it may store or retrieve information on your browser, mostly in the form of cookies. The chlorine is coming out the page while bromine is going into the page. This is even more important when you start to have branched chains of carbon atoms. 2) below. Curved double barbed arrows indicates the flow of two electrons. A molecular formula shows only the number and type of atoms in a molecule. In a line structure, carbon-carbon bonds are represented by a single line and hydrogen atoms are completely omitted, allowing organic chemists to quickly draw structures with long chains. May 28, 2024 · As stated previously, organic chemists use several different notations to represent organic molecules. They are: Expanded structural formula; Condensed structural formula; Bond-line/Skeletal structural formula Sep 9, 2021 · Video advice: Reading Skeletal Line Structures (Organic Chemistry), Parts 2 & 3 Watch this video on YouTube For anything other than the most simple molecules, drawing a fully displayed formula is a bit of a bother – especially all the carbon-hydrogen bonds. Consider a case where you have four CH 3 groups attached to a carbon. There are several types, including Dec 22, 2011 · Thanks James. Miscellaneous: Epoxides, Thioethers, Nitro, Imine, Azide. Although English reads from left to right, the best way to read a structure's name is from right to left. kastatic. These names are listed within the discussion of naming alkanes. Hybridization. Carbon atoms aren’t usually shown. Determine the structural feature that classifies amines as primary, secondary, or tertiary. I was wondering why Cycloalkanes are cyclic hydrocarbons, meaning that the carbons of the molecule are arranged in the form of a ring. Feb 13, 2019 · Functional groups are to organic chemistry what ions are to general chemistry. Examples of line notations include the Wiswesser Line-Formula Notation (WLN) 1, Sybyl Line Notation (SLN) 2, 3 and Representation of structure diagram arranged linearly If you look ahead in this chapter and in other resources at the way organic compounds are drawn, you will see that the figures are somewhat different from the Lewis structures you are used to seeing in your general chemistry book. They are widely used in Cheminformatics because computers can easily process linear strings of data. In skeletal structures , only the bonds and not the atoms are shown. 1 Lewis Structure of Diatomic Molecules. 2 Interpreting Mass Spectra - Organic Chemistry In the early stages of an organic chemistry course people frequently get confused and daunted by the names because they try to do too much at once. 2: Atomic Structure - The Nucleus Atoms are comprised of protons, neutrons and electrons. The term “organic” emanated from the misconception that organic compounds were always related to life processes. 6. Chemical structure determines the molecular geometry of the molecule. Different compounds having the same molecular formula are called isomers , and the prevalence of organic isomers reflects the extraordinary versatility of carbon in forming strong bonds to Organic compounds contain carbon atoms bonded hydrogen and other carbon atoms. It covers topics such as polar an May 23, 2021 · Learning Objectives. 1. Most of the compounds studied in organic chemistry contain at least one Try using your model kit to see that the OH group cannot lie in the same plane at the carbon chain (don’t forget your hydrogens!). Chemical structures are usually represented by the skeletal formula, which provides a graphical representation of the molecule with most hydrogens omitted for clarity. In the final 2Dexample, both dashed and wedged lines are used because the attached atoms are not hydrogens (although dashed and wedged lines can be used for hydrogens). 4 Development of Chemical Bonding Theory; 1. A molecular formula shows only the kinds and numbers of atoms in a molecule. 5 Describing Chemical Bonds: Valence Bond Theory; 1. Jul 31, 2021 · Conformational Drawings; Planar Structures; Projection Formulas; Contributors and Attributions; Many problems in organic chemistry require consideration of structures in three dimensions, and it is very helpful to use molecular models to visualize the relative positions of the atoms in space. In this chapter, you will learn how to identify the hybrid orbitals of an atom and how they affect the geometry and polarity of organic compounds. While a molecular formula only indicates the types and quantities of elements that are present in a molecule, nearly all of the compositional characteristics of an organic substance can be determined by analyzing a structure that is symbolized using expanded structural notation. At some point, when the structure is long enough, it is called a protein. The carbon-hydrogen bonds are not shown, but can be calculated by subtracting the number of C-C bonds on each carbon atom from four. Some examples are: Jan 16, 2023 · Organic chemistry consists of the study of organic molecules, including their formations, reactions, mechanisms of reactions, product formation, and uses. There are many different ways to represent the structure of a polypeptide or protein, each showing differing amounts of information. Some hydrocarbons have one or more carbon–carbon double bonds (denoted C=C). 2: Nomenclature of Alkanes; 2. These electrons have a high enough energy to knock an electron off an organic molecule to form a positive ion. Moore, Department of Chemistry, University of Illinois at Urbana-Champaign. Hybridization is a simple model that deals with mixing orbitals to from new, hybridized, orbitals. Dec 16, 2021 · Solution: The two resonance structures in this example are non-equivalent, so one is more stable than the other. Identify the general structure for an amine. 3: Functional Groups; 2. Dec 5, 2018 · How to write Lewis structures – There are several simple rules that allow us to draw proper Lewis structures: Rule (1) for writing Lewis structures (1) Lewis structures show the connections between atoms in a molecule or ion using only the valence electrons of the atoms involved. Remember, in phenol, the hydrogen attached to oxygen was labeled in the line structure. The two structures on the left are fairly obviously the same - all we've done is flip the molecule over. More specifically, you will learn how to convert 2D cyclohexane structures into 3D chair conformations, determine the stability of the conformation, and complete a chair flip. , should be placed as they appear in the Bond-Line structure. Learn the basics of organic chemistry structures, such as skeletal, Lewis-type, condensed, and bond-line formulas. Jan 23, 2023 · Through general chemistry, you may have already experienced looking at molecular structure. 7: Answers to Practice Questions Chapter 2 Newman projections are drawings used to help visualize the 3-dimensional structure of an organic molecule. To learn about Lewis structures, we will start with the Lewis symbol. As we begin to consider and study organic molecules we very quickly are faced with this fact: molecular structures (showing the number and types of atoms in a molecule, such as H 2 O) are inadequate to describe these substances. Aug 20, 2024 · 400+ free articles on undergraduate organic chemistry topics plus free (and paid) study guides, a reaction encyclopedia, practice problems, tutoring & more. Writing out Lewis structures can be at times, tricky and somewhat difficult. If you're behind a web filter, please make sure that the domains *. Organic Structures: Summary (so far) C C H H H H H O H Lewis Structure Ethanol C C H H H H H O H Kekulé Structure ¸ Organic Chemistry ¸ Relationship of Structure, Energy, and Reactivity The video illustrates how to read organic molecules drawings and determine the hidden hydrogens Because organic compounds can be complex at times, line-angle formulas are used to write carbon and hydrogen atoms more efficiently by replacing the letters with lines. 3 Atomic Structure: Electron Configurations; 1. This is part of the valence bond theory and helps explain bonds formed, the length of bonds, and bond energies; however, this does not explain molecular geometry very well. Jan 30, 2023 · Introduction. Lewis structures, skeletal structures, and condensed formulas for pentane, propene, and 4-methyl-2-pentanone. As organic chemistry grew and developed, many compounds were given trivial names, which are now commonly used and recognized. Jan 30, 2023 · Chemical Shift. In general, the base part of the name reflects the number of carbons in what you have assigned to be the parent chain . 1 Atomic Structure: The Nucleus; 1. The names and structures of some alcohols demonstrate the use of IUPAC rules. 2 Lewis Structure A Lewis structure shows the bonding between atoms as short lines (some books use pairs of dots) and non-bonding valence electrons as dots. Chemical Structure is the spatial arrangement of atoms in a molecule. Sep 11, 2020 · Ring structures in organic molecules are usually five-membered or six-membered. In condensed structures, carbon–hydrogen and carbon–carbon single bonds aren’t shown; instead, they’re understood. 12. Jan 23, 2023 · Introduction. The different ways to draw organic molecules include Keku l é (straight-line), Condensed Formul as, and Bond-Line Formulas (zig-zag). Identify the functional group for amines. Mar 26, 2016 · It's just as important to be able to determine and draw the structure of an organic molecule from its name as it is to be able to determine the name of its structure. Jan 23, 2023 · In the early stages of an organic chemistry course people frequently get confused and daunted by the names because they try to do too much at once. Jul 18, 2023 · We use several kinds of formulas to describe organic compounds. 2 Atomic Structure: Orbitals; 1. During this course, you will view molecules written in all three forms. Worldwide, the International Union of Pure and Applied Chemistry (IUPAC) has developed the system of nomenclature for organic compounds. Organic chemistry studies the properties and reactions of organic compounds. Watch video examples and practice exercises. Hydrogen atoms are then assumed to complete each of carbon's four bonds. Three-and four-membered rings are occasionally found in nature, but are significantly higher in energy. For example, the molecular formula C 4 H 10 tells us there are 4 carbon atoms and 10 hydrogen atoms in a molecule, but it doesn’t distinguish between butane and isobutane.   We simply must be able to recognize and distinguish between functional grouops to learn organic chemistry. 1 2 ethanediol and propane 1 2 3 triol are shown to highlight rule 3 Figure \(\PageIndex{1}\): IUPAC Rules for Alcohols. a. An expanded structural formula Dec 11, 2018 · Read Chemistry December 11, 2018 Organic Chemistry ** Organic chemists use a variety of formats to write structural formulas. These hydrocarbons are called alkenes (see section 3. Aug 14, 2021 · We use several kinds of formulas to describe organic compounds. RULE 1. Learn how to draw skeletal structure or bond-line notation for organic molecules with this easy tutorial. Give the condensed formula for the compound represented by this line-angle structure: 4. Nov 22, 2022 · Bond-line Structures . They represent a side view of a C-C alkane, or a single bond, as well as its side groups in each direction; they help to easily visualize the orientation of all the atoms or molecules bonding to the carbon represented by lines, dashes, or Sep 15, 2022 · Structures of 2 methylbutan-2-ol, 3 5-dimethylhexan-1-ol, 6 methylheptan-3-ol, 2 bromo 5 chlorocyclopentanol are shown to highlight rules 1 and 2. Come back to them as they arise during the natural flow of your In organic chemistry, skeletal formulae are the most abbreviated diagrammatic descriptions of molecules in common use. Come back to them as they arise during the natural flow of your Oct 3, 2014 · If there's one thing you learn in organic chemistry – it's how to draw a hexagon. Learning how to name organic compounds is the foundation upon which your entire organic chemistry knowledge will be based. All organic molecules have a hydrocarbon chain. Oct 21, 2014 · As an organic chemistry student, organic chemistry IUPAC nomenclature will be one of the first topics you encounter. Much of organic In fact, C 3 H 8 O can be one of 3 completely different molecules with different names, structures, physical and chemical properties! Molecular formulas are, however, the least useful type of molecular representation in organic chemistry. A carbon atom is present wherever a line intersects another line. They look very bare because in skeletal formulae the hydrogen atoms (attached directly to carbons) are removed, leaving just a ' carbon skeleton ' with functional groups attached to it. This is a super important skill in any college or university organic chemistry Resonance structures are required throughout organic chemistry. The following structures again all represent the same molecule - 2-methylbutane. tuneon usz geiswi xmviz tqpt albb hfrpgx howdc ayoor ttdodm